#include <iostream>

using namespace std;

void countdown(int n);

int main()
{
    countdown(4);

    return 0;
}

void countdown(int n)
{
    cout << "Counting down ... " << n << endl;
    if (n > 0)
    {
        countdown(n - 1);
    }
    cout << n << " end!\n";
}
